function [ stop ]=test_gamma(gamma)
    %TEST_GAMMA test if gamma is correct
    %   Usage:  stop = test_gamma(gamma)
    %           test_gamma(gamma)
    %
    %   Input parameters:
    %         gamma : number
    %   Output parameters:
    %         stop  : boolean
    %
    %   This function test is to make sure gamma is stricly positive
    %   
    %   If gamma is negative, this function return an error. If gamma is zero
    %   this function, set stop to 1.
    %
    % Author:  Nathanael Perraudin
    % Date: February 2012
    %

    if gamma<0
        error('gamma can not be negative!');
    % elseif (gamma==0) && warning
    %     gamma=gamma+eps;
    %     fprintf(' WARNING!!! gamma is 0. We add eps to gamma to keep going...\n');
    % else
    %   % gamma = gamma; 
    end

    if gamma==0
        stop = 1;
    else
        stop = 0;
    end

end